The use of capillary electrochromatography for natural product analysis - theoretical background and recent applications

Current Organic Chemistry

Volumn 14, Issue 16, 2010, Pages 1769-1780

  Ganzera, M ^a   Nischang, I ^b  

^a UNIVERSITY OF INNSBRUCK   (Austria)

^b JOHANNES KEPLER UNIVERSITY LINZ   (Austria)

Author keywords

Applications; CEC; Column technology; Natural products; Review

Indexed keywords

SILICA;

BASIC CONCEPTS; BASIC PRINCIPLES; CAPILLARY ELECTROCHROMATOGRAPHY; CEC; COLUMN TECHNOLOGY; IN CONTEXTS; NATURAL PRODUCT ANALYSIS; NATURAL PRODUCTS; STATIONARY PHASE; TECHNIQUE ADVANTAGE;

PACKED BEDS;

EID: 78649954444     PISSN: 13852728     EISSN: None     Source Type: Journal    
DOI: 10.2174/138527210792927726     Document Type: Article

References (112)

1. Probstein, R. F. Physicochemical Hydrodynamics, John Wiley and Sons: New York, 1994.
2. Pretorius, V.; Hopkins, B. J.; Schieke, J. D. Electro-osmosis: A new concept for high-speed liquid chromatography. J. Chromatogr. A, 1974, 99, 23-30.
3. Jorgenson, J. W.; Lukacs, K. D. High-resolution separations based on electrophoresis and electroosmosis. J. Chromatogr. A, 1981, 218, 209-216.
4. Knox, J. H.; Grant, I. H. Miniaturization in pressure and electroosmotically driven liquid-chromatography-Some theoretical considerations. Chromatographia, 1987, 24, 135-143.
5. Knox, J. H.; Grant, I. H. Electrochromatography in packed tubes using 1.5 to 50 μm silica-gels and ODS bonded silica-gels. Chromatographia, 1991, 32, 317-328.
6. Choudhary, G.; Horvath, C. Dynamics of capillary electrochromatography experimental study on the electrosmotic flow and conductance in open and packed capillaries. J. Chromatogr. A, 1997, 781, 161-183.
7. Wen, E.; Asiaie, R.; Horvath, C. Dynamics of capillary electrochromatography: II. Comparison of column efficiency parameters in microscale highperformance liquid chromatography and capillary electrochromatography. J. Chromatogr. A, 1999, 855, 349-366.
8. Nischang, I.; Tallarek, U. Fluid dynamics in capillary and chip electrochromatography. Electrophoresis, 2007, 28, 611-626.
9. Peters, E. C.; Petro, M.; Svec, F.; Frechet, J. M. J. Molded rigid polymer monoliths as separation media for capillary electrochromatography. 1. Fine control of porous properties and surface chemistry. Anal. Chem., 1998, 70, 2288-2295.
10. Peters, E. C.; Petro, M.; Svec, F.; Frechet, J. M. J. Molded rigid polymer monoliths as separation media for capillary electrochromatography. 2. Effect of chromatographic conditions on the separation. Anal. Chem., 1998, 70, 2296-2302.
11. Ericson, C.; Holm, J.; Ericson, T.; Hjerten, S. Electroosmosis-and pressuredriven chromatography in chips using continuous beds. Anal. Chem., 2000, 72, 81-87.
12. Deyl, Z.; Svec, F. (Eds)., Capillary Electrochromatography. Journal of Chromatography Library, Elsevier, Amsterdam, 2001, Vol. 62.
13. Minakuchi, H.; Nakanishi, K.; Soga, N.; Ishizuka, N.; Tanaka, N. Octadecylsilylated porous silica rods as separation media for reversed-phase liquid chromatography. Anal. Chem., 1996, 68, 3498-3501.
14. Mayer, M.; Rapp, E.; Marck, C.; Bruin, G. J. Fritless capillary electrochromatography. Electrophoresis, 1999, 20, 43-49.
15. Rapp, E.; Bayer, E. Improved column preparation and performance in capillary electrochromatography. J. Chromatogr. A, 2000, 887, 367-378.
16. Piraino, S. M.; Dorsey, J. G. Comparison of frits used in the preparation of packed capillaries for capillary electrochromatography. Anal. Chem., 2003, 75, 4292-4296.
17. Legido-Quigley, C.; Marlin, N. D.; Melin, V.; Manz, A.; Smith, N. W. Advances in capillary electrochromatography and micro-high performance liquid chromatography monolithic columns for separation science. Electrophoresis, 2003, 24, 917-944.
18. Eeltink, S.; Svec, F. Recent advances in the control of morphology and surface chemistry of porous polymer-based monolithic stationary phases and their application in CEC. Electrophoresis, 2007, 28, 137-147.
19. Nischang, I.; Svec, F.; Frechet, J. M.J. Effect of capillary cross-section geometry and size on the separation of proteins in gradient mode using monolithic poly(butyl methacrylate-co-ethylene dimethacrylate) columns. J. Chromatogr. A, 2009, 1216, 2355-2361.
20. Nakanishi, K.; Tanaka, N. Sol-gel with phase separation. Hierarchically porous materials optimized for high-performance liquid chromatography separations. Acc. Chem. Res., 2007, 40, 863-873.
21. Aoki, H.; Tanaka, N.; Kubo, T.; Hosoya, K. Polymer-based monolithic columns in capillary format tailored by using controlled in situ polymerization. J. Sep. Sci., 2009, 32, 341-358.
22. Colon, L. A.; Maloney, T. D.; Fermier, A. M. Packing columns for capillary electrochromatography. J. Chromatogr. A, 2000, 887, 43-53.
23. Choudhary, G.; Apffel, A.; Yin, H.; Hancock, W. Use of on-line mass spectrometric detection in capillary electrochromatography. J. Chromatogr. A, 2000, 887, 85-101.
24. Klampfl, C. W. Coupling of capillary electrochromatography to mass spectrometry. J. Chromatogr. A, 2004, 1044, 131-144.
25. Bandilla, D.; Skinner, C. D. Capillary electrochromatography of peptides and proteins. J. Chromatogr. A, 2004, 1044, 113-129.
26. Kasicka, V. Recent developments in CE and CEC of peptides. Electrophoresis, 2008, 29, 179-206.
27. Fanali, S.; Catarcini, P.; Blaschke, G.; Chankvetadze, B. Enantioseparations by capillary electrochromatography. Electrophoresis, 2001, 22, 3131-3151.
28. Schaller, D.; Hilder, E. F.; Haddad, P. R. Monolithic stationary phases for fast ion chromatography and capillary electrochromatography of inorganic ions. J. Sep. Sci., 2006, 29, 1705-1719.
29. Bek-Zlotorzynska, E.; Celo, V. Recent advances in capillary electrophoresis and capillary electrochromatography of pollutants. Electrophoresis, 2006, 27, 304-322.
30. Freitag, R.; Hilbrig, F. Theory and practical understanding of the migration behavior of proteins and peptides, in CE and related techniques. Electrophoresis, 2007, 28, 2125-2144.
31. Svec, F. CEC: selected developments that caught my eye since the year 2000. Electrophoresis, 2009, 30 (Suppl 1), S68-S82.
32. Steiner, F.; Scherer, B. Instrumentation for capillary electrochromatography. J. Chromatogr. A, 2000, 887, 55-83.
33. Rathore, A. S.; Horvath, C. Theories of electroosmotic flow in porous media. J. Chromatogr. A, 1997, 781, 185-195.
34. Nischang, I.; Chen, G.; Tallarek, U. Electrohydrodynamic in hierarchically structured monolithic and particulate fixed beds. J. Chromatogr. A, 2006, 1109, 32-50.
35. Szumski, M.; Kucerova, Z.; Jandera, P.; Buszewski, B. EOF in monolithic poly(styrene-co-divinylbenzene) capillary columns. Electrophoresis, 2009, 30, 583-588.
36. Liu, Z.; Wu, R.; Zou, H.F. Recent progress in adsorbed stationary phases for capillary electrochromatography. Electrophoresis, 2002, 23, 3954-3972.
37. Sanchez Munoz, O. L.; Hernandez, E. P.; Lammerhofer, M.; Lindner, W.; Kenndler, E. Estimation and comparison of zeta-potentials of silica-based anion-exchange type porous particles for capillary electrochromatography from electrophoretic and electroosmotic mobility. Electrophoresis, 2003, 24, 390-398.
38. Kirby, B. J.; Hasselbrink, E. F. Zeta potential of microfluidic substrates: 1. Theory, experimental techniques, and effects on separations. Electrophoresis, 2004, 25, 187-202.
39. Kirby, B. J.; Hasselbrink, E. F. Zeta potential of microfluidic substrates: 2. Data for polymers. Electrophoresis, 2004, 25, 203-213.
40. Steiner, F.; Scherer, B. Separation of small peptides by electrochromatography on silica-based reversed phases and hydrophobic anion exchange phases. Electrophoresis, 2005, 26, 1996-2004.
41. Stol, R.; Poppe, H.; Kok, W. T. Effects of pore flow on the separation efficiency in capillary electrochromatography with porous particles. Anal. Chem., 2001, 73, 3332-3339.
42. Vallano, P. T.; Remcho, V. T. Modeling interparticle and intraparticle (perfusive) electroosmotic flow in capillary electrochromatography. Anal. Chem., 2000, 72, 4255-4265.
43. Luedtke, S.; Adam, T.; von, D. N.; Unger, K. K. Towards the ultimate minimum particle diameter of silica packings in capillary electrochromatography. J. Chromatogr. A, 2000, 887, 339-346.
44. Preinerstorfer, B.; Lammerhofer, M.; Hoffmann, C. V.; Lubda, D.; Lindner, W. Deconvolution of electrokinetic and chromatographic contributions to solute migration in stereoselective ion-exchange capillary electrochromatography on monolithic silica capillary columns. J. Sep. Sci., 2008, 31, 3065-3078.
45. Nischang, I.; Spannmann, K.; Tallarek, U. Key to analyte migration and retention in electrochromatography. Anal. Chem., 2006, 78, 3601-3608.
46. Nischang, I.; Reichl, U.; Seidel-Morgenstern, A.; Tallarek, U. Concentration polarization and nonequilibrium electroosmotic slip in dense multiparticle systems. Langmuir, 2007, 23, 9271-9281.
47. Loeser, E.; Drumm, P. Evaluating the surface charge of C18 stationary phases. Anal. Chem., 2007, 79, 5382-5391.
48. Jandera, P.; Bocian, S.; Molikova, M.; Buszewski, B. Characterization of the properties of stationary phases for liquid chromatography in aqueous mobile phases using aromatic sulphonic acids as the test compounds. J. Chromatogr. A, 2009, 1216, 237-248.
49. Nischang, I.; Holtzel, A.; Seidel-Morgenstern, A.; Tallarek, U. Concentration polarization and nonequilibrium electroosmotic slip in hierarchical monolithic structures. Electrophoresis, 2008, 29, 1140-1151.
50. Xiang, R.; Horvath, C. Fundamentals of capillary electrochromatography: Migration behavior of ionized sample components. Anal. Chem., 2002, 74, 762-770.
51. Chen, G.; Tallarek, U.; Seidel-Morgenstern, A.; Zhang, Y. Influence of moderate Joule heating on electroosmotic flow velocity, retention, and efficiency in capillary electrochromatography. J. Chromatogr. A, 2004, 1044, 287-294.
52. Rathore, A. S. Joule heating and determination of temperature in capillary electrophoresis and capillary electrochromatography columns. J. Chromatogr. A, 2004, 1037, 431-443.
53. Ivanov, A. R.; Zang, L.; Karger, B. L. Low-attomole electrospray ionization MS and MS/MS analysis of protein tryptic digests using 20-mu m-i.d. polystyrene-divinylbenzene monolithic capillary columns. Anal. Chem., 2003, 75, 5306-5316.
54. Hsieh, S.; Jorgenson, J. W. Preparation and evaluation of slurry-packed liquid chromatography microcolumns with inner diameters from 12 to 33 μm. Anal. Chem., 1996, 68, 1212-1217.
55. Mair, D. A.; Schwei, T. R.; Dinio, T. S.; Svec, F.; Frechet, J. M. Use of photopatterned porous polymer monoliths as passive micromixers to enhance mixing efficiency for on-chip labeling reactions. Lab Chip, 2009, 9, 877-883.
56. Logan, T. C.; Clark, D. S.; Stachowiak, T. B.; Svec, F.; Frechet, J. M.J. Photopatterning enzymes on polymer monoliths in microfluidic devices for steady-state kinetic analysis and spatially separated multi-enzyme reactions. Anal. Chem., 2007, 79, 6592-6598.
57. Gu, B. H.; Armenta, J. M.; Lee, M. L. Preparation and evaluation of poly (polyethylene glycol methyl ether acrylate-co-polyethylene glycol diacrylate) monolith for protein analysis. J. Chromatogr. A, 2005, 1079, 382-391.
58. Eeltink, S.; Hilder, E. F.; Geiser, L.; Svec, F.; Frechet, J. M.; Rozing, G. P.; Schoenmakers, P. J.; Kok, W. T. Controlling the surface chemistry and chromatography properties of methyacrylate-ester-based monolithic capillary colums via photografting. J. Sep. Sci., 2007, 30, 407-413.
59. Peterson, D. S.; Rohr, T.; Svec, F.; Frechet, J. M.J. Dual-function microanalytical device by in situ photolithographic grafting of porous polymer monolith: Integrating solid-phase extraction and enzymatic digestion for peptide mass mapping. Anal. Chem., 2003, 75, 5328-5335.
60. Hilder, E. F.; Svec, F.; Frechet, J. M.J. Shielded stationary phases based on porous polymer monoliths for the capillary electrochromatography of highly basic biomolecules. Anal. Chem., 2004, 76, 3887-3892.
61. Paces, M.; Kosek, J.; Marek, M.; Tallarek, U.; Seidel-Morgenstern, A. Mathematical modelling of adsorption and transport processes in capillary electrochromatography: Open-tubular geometry. Electrophoresis, 2003, 24, 380-389.
62. Mair, D. A.; Geiger, E.; Pisano, A. P.; Frechet, J. M.; Svec, F. Injection molded microfluidic chips featuring integrated interconnects. Lab Chip, 2006, 6, 1346-1354.
63. Guiochon, G. Monolithic columns in high-performance liquid chromatography. J. Chromatogr. A, 2007, 1168, 101-168.
64. Eeltink, S.; Decrop, W. M.; Rozing, G. P.; Schoenmakers, P. J.; Kok, W. T. Comparison of the efficiency of microparticulate and monolithic capillary columns. J. Sep. Sci., 2004, 27, 1431-1440.
65. Luo, Q.; Yue, G.; Valaskovic, G. A.; Gu, Y.; Wu, S. L.; Karger, B. L. Online 1D and 2D porous layer open tubular/LC-ESI-MS using 10-mu m-i.d. poly(styrene-divinylbenzene) columns for ultrasensitive proteomic analysis. Anal. Chem., 2007, 79, 6174-6181.
66. Eeltink, S.; Svec, F.; Frechet, J. M. J. Open-tubular capillary columns with a porous layer of monolithic polymer for highly efficient and fast separations in electrochromatography. Electrophoresis, 2006, 27, 4249-4256.
67. Otieno, A.C.; Mwongela, S.M. Capillary electrophoresis based methods for the determination of lipids - a review. Anal. Chim. Acta, 2008, 624, 163-174.
68. Garcia-Cañas, V.; Cifuentes, A. Recent advances in the application of capillary electromigration methods for food analysis. Electrophoresis, 2008, 29, 294-309.
69. Huo, Y.; Kok, W.T. Recent applications in CEC. Electrophoresis, 2008, 29, 80-93.
70. Scherz, H.; Huck, C.W.; Bonn, G.K. CEC and EKC of natural compounds. Electrophoresis, 2007, 28, 1645-1657.
71. Klampfl, C.W. Determination of organic acids by CE and CEC methods. Electrophoresis, 2007, 28, 3362-3378.
72. Kučerová, Z.; Szumski, M.; Buszewski, B.; Jandera, P. Alkylated poly(styrene-divenyl benzene) monolithic columns for μ-HPLC and CEC separation of phenolic acids. J. Sep. Sci., 2007, 30, 3018-3026.
73. Lin, Z.; Xie, Z. Direct determination of amino acids by pressurized capillary electrochromatography with chemiluminescence detection. J. Sep. Sci., 2008, 31, 2852-2859.
74. Xie, C.; Hu, J.; Xiao, H.; Su, X.; Dong J.; Tian, R.; He, Z.; Zou, H. Electrochromatographic evaluation of a silica monolith capillary for separation of basic pharmaceuticals. Electrophoresis, 2005, 26, 790-797.
75. Xie, C.; Hu, J.; Xiao, H.; Su, X.; Dong, J.; Tian, R.; He, Z.; Zou, H. Preparation of a monolithic silica column with strong cation-exchange stationary phase for capillary electrochromatography. J. Sep. Sci., 2005, 28, 751-756.
76. Dong, J.; Ou, J.; Dong, X.; Wu, R.; Ye, M.; Zou, H. Preparation and evaluation of rigid porous poolyacrylamide-based strong cation-exchange monolithic columns for capillary electrochromatography. J. Sep. Sci., 2007, 30, 2986-2992.
77. Lin, X.; Wang, J.; Li, L.; Wang, X.; Lü, H.; Xie, Z. Separation and determination of five major opium alkaloids with mixed mode of hydrophilic/cationexchange monolith by pressurized capillary electrochromatogarphy. J. Sep. Sci., 2007, 30, 3011-3017.
78. Dong, J.; Xie, C.; Tian, R.; Wu, R.; Hu, J.; Zou, H. Capillary electrochromato-graphy with neutral monolithic column for classification of analytes and determination in human sera. Electrophoresis, 2005, 26, 3452-3459.
79. Ohyama, K.; Wada, M.; Lord, G.A.; Ohba, Y.; Nakashima, N.M.; Nakashima, K.; Akiyama, S.; Lim, C.K.; Kuroda, N. Capillary electrochromatography of caffeine and its metabolites in rat brain microdialysate. Electrophoresis, 2005, 26, 812-817.
80. Uysal, U.D.; Aturki, Z.; Raggi, M.A.; Fanali, S. Separation of catechins and methylxanthins in tea samples by capillary electrochromatography. J. Sep. Sci., 2009, 32, 1002-1010.
81. Chen, Y.; Fan, G.; Chen, B.; Xie, Y.; Wu, H.; Wu, Y.; Yan, C.; Wang, J. Separation and quantitative analysis of coumarin compounds from Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook. f by pressurized capillary electrochromatography. J. Pharm. Biomed. Anal., 2006, 41, 105-116.
82. Molnár-Perl, I.; Füzfai, Z. Chromatographic, capillary electrophoretic and capillary electrochromatographic techniques in the analysis of flavonoids. J. Chromatogr. A, 2005, 1073, 201-227.
83. Stalikas, C.D. Extraction, separation, and detection methods for phenolic acids and flavonoids. J. Sep. Sci., 2007, 30, 3268-3295.
84. Messina, A.; Desiderio, C.; De Rossi, A.; Bachechi, F.; Sinibaldi, M. Capillary electrochromatography on methacrylathe based monolithic columns: evaluation of column performance and separation of polyphenols. Chromatographia, 2005, 62, 409-416.
85. Karenga, S.; El Rassi, Z. Neutral octadecyl monolith for reversed phase capillary electrochromatography of a wide range of solutes. J. Sep. Sci., 2008, 31, 2677-2685.
86. Stöggl, W.M.; Huck, C.W.; Stecher, G.; Bonn, G.K. Capillary electrochromatography of biologically relevant flavonoids. Electrophoresis, 2006, 27, 787-792.
87. Desiderio, C.; De Rossi, A.; Sinibaldi, M. Analysis of 7-O-glycosides in citrus juices by short-end capillary electrochromatography. J. Chromatogr. A, 2005, 1081, 99-104.
88. Aturki, Z.; Fanali, S.; D'Orazio, G.; Rocco, A.; Rosati, C. Analysis of phenolic compounds in extra virgin olive oil by using reversed-phase capillary electrochromatography. Electrophoresis, 2008, 29, 1643-1650.
89. Wang, S.; Jia, L.; Chen, D. Pressurized CEC with gradient elution for the separation of flavonoids from corn. J. Sep. Sci., 2009, 32, 388-393.
90. Chen, X.; Ji, H.; Wang, Y.; Li, S. Simultaneous determination of seven flavonoids in Epimedium using pressurized liquid extraction and capillary electrochromatography. J. Sep. Sci., 2008, 31, 881-887.
91. Fonseca, F.N.; Tavares, M.; Horváth, C. Capillary electrochromatography of selected phenolic compounds of Chamomilla recutita. J. Chromatogr. A, 2007, 1154, 390-399.
92. Zhang, L.; Zhang, J.; Wang, H.; Zhang, L.; Zhang, W.; Zhang, Y. Analysis of flavonoids in Adinandra nitida by capillary electrochromatography on monolithic columns with stepwise gradient elution. J. Sep. Sci., 2005, 28, 774-779.
93. Wang, J.; Chen, Y.; Lin, M.; Fan, G.; Zhao, W.; Wu, Y.; Yan, C.; Wang, J. Development of a quality evaluation method for Fructus schisandrae by pressurized capillary electrochromatography. J. Sep. Sci., 2007, 30, 381-390.
94. Ganzera, M.; Stöggl, W.; Bonn, G.; Khan, I.; Stuppner, H. Capillary electrochromatography of boswellic acids in Boswellia serrata Roxb. J. Sep. Sci., 2003, 26, 1383-1388.
95. Liu, S.; Xie, Z.; Wu, X.; Lin, X.; Guo, L.; Chen, G. Separation of structurally related estrogens using isocratic elution pressurized capillary electrochromatography. J. Chromatogr. A, 2005, 1092, 258-262.
96. Musenga, A.; Mandrioli, R.; Ferrati, A.; D'Orazio, G.; Fanali, S.; Raggi, M.A. Analysis of aromatic and terpenic constituents of pepper extracts by capillary electrochromatography. J. Sep. Sci., 2007, 30, 612-619.
97. Li, P.; Li, S.P.; Yang, F.Q.; Wang, Y.T. Simultaneous determination of four tashinones in Salvia miltiorrhiza by pressurized liquid extraction and capillary electrochromatography. J. Sep. Sci., 2007, 30, 900-905.
98. Lerma-Garcia, M.J.; Simó-Alfonso, E.; Ramis-Ramos, G.; Herrero-Martinez, J. Rapid determination of sterols in vegetable oils by CEC using methacrylate ester-based monolithic columns. Electrophoresis, 2008, 29, 4603-4611.
99. Bo, T.; Liu, H. Separation methods for pharmacologically active xanthones. J. Chromatogr. B, 2004, 812, 165-174.
100. Lü, H.; Wang, J.; Wang, X.; Lin, X.; Wu, X.; Xie, X. Rapid separation of structurally related anthraquinones in rhubarb by pressurized capillary electrochromatography. J. Pharm. Biomed. Anal., 2007, 43, 352-357.
101. Lerma-Garcia, M.J.; Simó-Alfonso, E.; Ramis-Ramos, G.; Herrero-Martiez, J. Determination of tocopherols in vegetable oils by CEC using methacrylate ester-based monolithic columns. Electrophoresis, 2007, 28, 4128-4135.
102. Chaisuwan, P.; Nacapricha, D.; Wilairat, P.; Jiang, Z.; Smith, N.W. Separation of α-, β-, γ-, δ-tocopherols and α-tocopherol acetate on a pentaerythritol diacrylate monostearate-ethylene dimethacrylate monolith by capillary electrochromatography. Electrophoresis, 2008, 29, 2301-2309.
103. Herrero-Martinez, J.; Eeltink, S.; Schoenmakers, P.; Kok, W.T.; Ramis-Ramos, G. Determination of major carotinoids in vegetables by capillary electrochro-matography. J. Sep. Sci., 2006, 29, 660-665.
104. Adalid, A.M.; Herrero-Martinez, J.; Rosello, S.; Maquieira, A.; Nuez, F. Fast determination of prominent carotinoids in tomato fruits by CEC using methacrylate ester-based monolithic columns. Electrophoresis, 2007, 28, 4120-4127.
105. Jia, L.; Liu, Y.; Du, Y.; Xing, D. Pressurized capillary electrochromatographic analysis of water-soluble vitamins by combining with on-line concentration technique. J. Chromatogr. A, 2007, 1154, 416-422.
106. Ye, F.; Xie, Z.; Wu, X.; Lin, X. Determination of pesticide residues in vegetables by pressurized capillary electrochromatography. Talanta, 2006, 69, 97-102.
107. Wang, S.; Jia, L.; Xing, D.; Chen, D.; Zhao, J. On-line concentration and pressurized capillary electrochromatographic analysis of phytohormones incorn. J. Sep. Sci., 2008, 31, 859-864.
108. Liu, C.Y.; Chen, T.H.; Misra, T.K. A macrocyclic polyamine as an anion receptor in the capillary electrochromatographic separation of carbohydrates. J. Chromatogr. A, 2007, 1154, 407-415.
109. Yang, F.Q.; Li, S.; Li, P.; Wang, Y.T. Optimization of CEC for simultaneous determination of eleven nucleosides and nucleobases in Cordyceps using central composite design. Electrophoresis, 2007, 28, 1681-1688.
110. Jia, Y.; Tan, X.; Li, Q.; Cheng, W.; Chen, X.; Bi, K. Quality control of TCMs using a chromatographic fingerprint. Asian J. Trad. Med., 2006, 1, 94-100.
111. Xie, G.; Qiu, M.F.; Zhao, A.H.; Jia, W. Fingerprint analysis of Flos Carthami by pressurized CEC and LC. Chromatographia, 2006, 64, 739-743.
112. Xie, G.; Zhao, A.; Li, P.; Li, L.; Jia, W. Fingerprint analysis of Rhizoma chuanxiong by pressurized capillary electrochromatography and highperformance liquid chromatography. Biomed. Chromatogr., 2007, 21, 867-875.